In July, the state of California put into effect the updated standards of its Title 24 building code, which includes increased stringency in its Energy Efficiency Standards for Residential and Nonresidential Buildings.
According to a summary by Title 24 Express, which provides certifications and reports for residential and commercial projects, Title 24’s “mandatory measures require that both the U-factor and the solar heat gain coefficient (SHGC) of manufactured fenestration products be determined from NFRC’s Certified Product Directory or from the California Energy Commission approved default tables.”
In addition to changes of window performance, daylighting requirements were also altered.
Those standards have become more rigid in the updated code, as they reduced the U-factor and SHGC while increasing the requirement for visible light transmission. The Title 24 energy code allows for two avenues of compliance—the prescriptive method or the performance method.
“Under the prescriptive method, each component of the building envelope must meet a specific, prescriptive energy-efficiency requirement,” says Brandon Tinianov, senior director of business development at View. “The prescriptive approach is the simplest but also the least flexible, as even if one component does not comply, another compliance method must be chosen.”
He adds, “Under the Performance method, the building is measured by its overall energy output using a computer-simulated building model that is compared to a baseline building modeled with components that comply with the prescriptive requirements. This allows more flexibility to the architect who can choose certain products that do not comply with the prescriptive requirements as long as the overall building energy use is lower than that required and therefore compliant.”
Title 24 is one of the most rigid codes in the U.S., and given the significance glass and fenestration plays in the conservation of energy, industry manufacturers have had to be proactive in educating architects, builders and dealers in how the updated code affects the industry.
“About one-third of the heating and cooling of a building passes through [fenestration],” says Ray McGowan, senior program manager at the National Fenestration Rating Council (NFRC).
Western Window Systems recently developed an online tool to act as a guide to the new Title 24 standards as they relate to fenestration. Western is based out of Phoenix, and California is a major market for the company.
“We felt we needed to come out with something that educated the industry—whether it’s the homeowner, architect, dealer or builder—put something in their hands so that anyone reading it could understand what the actual requirements are,” says Andrew Darr, vice president of custom sales at Western. Darr says that the performance method “gives people the ability to make educated decisions about what they want” and “gives people a more flexible path,” something the users of Western’s products—largely of the high-end residential sector—are seeking.
“California is home to lots of modern architecture and architects,” he says, adding that many of those projects utilize large amounts of glass.
LaCantina Doors, based out of Oceanside, Calif., posted a blog earlier this year regarding Title 24, and glazing contractors have also gotten into the educational resource action, as Old Town Glass, based in Downtown Novato, Calif., wrote a Title 24 blog post for customers’ reference.
California-based View has literature on its website specific to Title 24, as well, as Tinianov says the increased stringency’s effect on dynamic glass—which continues to build its presence in the nonresidential sector—is not lost.
“The new Title 24 revision has the dual requirements of more stringent glass performance requirements and additional building daylighting,” says Tinianov. “Typically these goals work against each other, but the California energy code recognizes dynamic glass’s ability to optimize both. We expect design teams to increase the use of dynamic glass to allow for additional glazing under the new requirements.”
The updated Building Energy Efficiency Standards for Residential and Non-Residential Buildings can be viewed here. Title 24 Express, which produces calculations and compliance reports for projects, has a summary on its website with a section specific to fenestration here.